A vehicle restraining apparatus of a type as shown in FIG. 33 is arranged to restrain a vehicle 102 having tires 102a on rollers 106 of chassis dynamometer 105 by using chains or wire ropes 101 so that first ends 101a of wire ropes 101 are connected with vehicle 102 and second or opposite ends 101b of wire ropes 10a are connected with poles 104 installed on a floor 103 (Patent documents 1, 2, for example).
Moreover, a vehicle restraining device 112 as shown in FIGS. 34(A) and 34(B) is under development. This vehicle restraining device 112 is arranged to slide along a rail 111, and to restrain a vehicle 116 with arm 114 which is supported by a arm support portion 113 of the vehicle restraining device 112, and which extends to a forward end portion provided with an adapter 115 fit in an adapter receiving portion 118 formed in a chassis 117 of the vehicle 116 to connect and restrain the vehicle (Patent Document 3, for example).
In a vehicle running on an actual road, the vertical load applied to each tire varies in dependence on the acceleration/deceleration. In the case of the chassis dynamometer, by contrast, each degree of freedom of the vehicle is restrained and hence
the vertical loads vary differently from the running condition on the actual road.
Between the running motion on the actual road and the running motion on the chassis dynamometer, the difference in the vehicle pitching motion causes a difference in the application of vertical loads, and exerts influence on the results of a test. Since the accuracy of the vehicle performance test is adversely influenced by the difference in changes in the vertical loads, it is required to reproduce the behavior of vehicle pitching motion.
In the case of the vehicle restraining apparatus using the chains or wire ropes 101 as shown in FIG. 33, the tires 102a of vehicle 102 are pressed on the rollers 106 by the chains or wire ropes 101, and therefore, the reproduction of the behavior of vehicle pitching motion is difficult.
The vehicle restraining apparatus of Patent document 3 is arranged to restrain the vehicle with the vehicle restraining device 112 which is movable on the rail 111 and which includes the adapter 115 inserted in the adapter receiving portion 118 formed in the chassis 117 of vehicle 116. Therefore, the reproduction of the vehicle pitching behavior is easier because the tires are not pressed on the rollers by the chains or wire ropes 101 as in Patent Documents 1 and 2. However, the vehicle restraining apparatus of Patent Document 3 encounters the following problems.
(1) The adapter receiving portion is generally formed in a side sill in the bottom of the vehicle, so that the application is difficult to vehicles having no side sills. For vehicles having no side sills, it is required to fix an attachment formed with the adapter receiving portion, to the bottom of the vehicle.
(2) The adapter receiving portion is required to be rigid enough for safety aspect. However, the side sills are not always rigid enough in the whole of the vehicle.
(3) The positions of side sills are away from the center of gravity of the vehicle, and the center of gravity of the vehicle is not restrained. Therefore, the vehicle pitching motion is varied differently from the actual behavior on the road.
The present invention has been devised to solve these problems.